How to Fix a Flickering Light Bulb

Close-Up Of Illuminated Light Bulb In Room
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Flickering light bulbs are a common household electrical problem. Addressing the issue is a simple matter, but the approach you take will depend on the exact reasons for the flickering. 

What Causes Flickering?

In general, flickering lights are caused by a simple drop or fluctuation in household voltage that causes the lights to dim momentarily. A variety of common issues can cause your lights to flicker, and understanding the specific causes will tell exactly what to do to solve it. 

Bulb type. Fluorescent lights are more prone to flickering than LED and other bulb types. Temperature, bulb age, and warm-up cycles are common causes of fluorescent flickering. Small amounts of flickering aren’t a cause for concern, but if constant flickering or dimming are occurring, replace your fluorescent bulb to correct it. 

Dimmer switches are a common source of flickering with LED bulbs. Most dimmers are manufactured for higher electrical loads. As a result, low-voltage LEDs can flicker and dim if they are paired with high-powered dimmer switches. It’s a good idea to check the bulb compatibility of your dimmer before purchasing new bulbs. Or, you can replace the dimmer switch with one appropriate for LED bulbs. 

Loose bulbs. Unseated bulbs rattle in their sockets, resulting in inconsistent connections and regular flickering. Simply tightening the bulb will ensure a solid connection and eliminate any dips in the current.

Faulty connections. A bad connection in your lamp or fixture’s on-off switch can result in flickering. Troubleshoot the connections by wiggling the on-off switch. If your lights dim as you do this, you probably have a bad switch. While lamp switches found along the lamp cord are easy to replace, they are more difficult to replace when they are integrated into the socket unit. In this case, replacing the entire switch/socket unit is the easier fix. If you're unsure how to tackle this project, a lamp repair shop can do it for very little money. Cord plugs can also be the source of bad electrical connections. Sometimes, bent or damaged prongs can create a bad connection. Simply straightening the prongs will sometimes cure the flickering, while in other cases you'll need to replace the plug. This is an easy enough DIY project, but again, a lamp shop can also do it. 

Large current draws. Larger appliances can pull 100 or more amps from the house wiring when they cycling on. This surge in power can cause your lights to momentarily dim and flicker. Call an electrician to ensure your appliances are wired correctly and aren’t overworking your home’s circuit.

When Flickering Indicates a Serious Problem

Flickering lights are normally not a cause for alarm. But sometimes they can indicate a more serious underlying issue. Constant or severe drops in lighting can result from faulty connections somewhere along the circuit.

Faulty wiring connections create points of high resistance, which can generate unsafe levels of heat.  Old breakers can also cause flickering. Faulty breaker wiring can short and overheat, which can cause lights to flicker. Always call a pro to address these problems.

Installing a New Fixture

Old or damaged fixtures can cause a variety of problems, including flickering. Here is an overview of how to install a new light fixture in your home:

  1. Turn off the power. Locate your circuit breaker box and turn off the breaker that controls the power to the room where you’ll be working. You can turn off your power main (the main breaker) if you’re unsure which individual breaker controls your room.
  2. Remove the fixture's globe or cover to reveal the mounting screws holding the fixture to the ceiling box. 
  3. Loosen the mounting screws to separate the fixture from the ceiling box and expose the wiring connections.
  4. Test for current, then disconnect the light fixture wires from the circuit wires. Usually, this involves simply unscrewing wire nut connectors, but the grounding lead may need to be unscrewed from a green grounding screw on the ceiling box mounting strap.
  5. Connect the neutral lead on the new fixture to the neutral circuit wire, using a wire connector (wire nut). Neutral wires are typically white. This is sometimes a bit of a balancing act, as you must hold the fixture with one hand while attaching the wire connections with the other. Having a helper can be very useful at this stage. 
  1. Connect the black (hot) fixture lead to the hot circuit wire, using a wire connector. 
  2. Connect the grounding lead on the new fixture to the circuit grounding system. The fixture's grounding lead may be a green insulated wire or bare copper wire, while the circuit grounding wire is usually bare copper. Depending on how your old fixture was wired, this may involve connecting the fixture lead directly to a circuit grounding wire, or attaching it to the green grounding screw on a metal ceiling box.
  3. To secure the fixture base to the ceiling box, fold the wires into the electrical box and push the fixture toward the ceiling. Thread the mounting screws through the base plate of the fixture and screw them into the corresponding holes in the ceiling box mounting strap. Tight securely.
  4. Install the light bulbs. Choose bulbs that do not exceed the overall wattage rating of the light fixture. Attach the fixture's globe or glass cover.
  5. Turn the power on. Flip the breaker to the on position to restore power to the light fixture, and test to make sure it is operating properly.

    Installing basic light fixtures is a relatively simple job, but it does require some basic wiring skills. Call a pro if you’re unsure about tackling this project yourself.